Some beginner's questions

[corsepiu at faw.uni-ulm.de (Ralf Corsepius)]

John Mills wrote:

> Hello -
> I have built RTEMS tools (sh-rtems-*) using 'bit' and rtems-4.0.0 using
> 'bit_rtems' under Gnu/Linux-2.2.5 (RH6.0), and the 'hello_world_c' example
> ('test.*') with apparent success. I will initially be targeting Hitachi's
> EDK7045F developer's board. My two next questions are:
>
> 1) How and from which directory should I invoke 'size_rtems' to get a scale
> for what was built, or is that appropriate at this stage?
>

IMO, this script is not worth the effort :-)

>
> 2) Where should I add code for a simple console, so it will be built into my
> executable?
>

At the moment the drivers for on-cpu devices of the sh are below
libcpu/sh/sh7032/<driver>

The  directory is named sh7032 because this was the processor we actually used
for porting RTEMS to the SH1.

In general, all drivers for on-chip devices of the sh1, should be compatible to
and reuseable on all variants of SH1, thus the name of this directory might be
chosen unfortunately.

I would suggest to use libcpu/sh/sh7032/<your-driver> as directory for the
driver, assuming that sh7230 should mean sh1.

>
> I have written serial I/O drivers as a stand-alone demo.
>

The SH port uses an approach that is different from all other ports of rtems.
Instead of having designated /dev/console we redirect /dev/console to other
serial devices, in a similar way a sym-link called /dev/console would point to
a serial device (eg. /dev/ttyS0) under unix. Which device to use as console is
specified via the define CPU_CONSOLE_DEVNAME.

I.e. to access your serial driver as  /dev/console, add
-DCPU_CONSOLE_DEVNAME=\"/dev/your-device\" to CPU_CFLAGS in your BSPs
make/custom/*.cfg file or add #define CPU_CONSOLE_DEVNAME "/dev/your-device" to
your BSP's libbsp/sh/<your-bsp>/include/bsp.h

cf libbsp/sh/gensh1/include/bsp.h

>
> I expect I need to touch the startup code as well as the console driver.

The standard approach is to start to write a BSP of your own if the code in
gensh1 doesn't match your requirements and can't be adapted by passing
suiteable CFLAGS etc. in make/custom/<your-bsp>.cfg.

I don't know the details about your board, so having to touch the startup code
might be possible, but I doubt you need to touch the console driver.

> I
> found the 'no_bsp_console' example, but need to know where to put a
> filled-in version and to have it linked.
>

Ralf

--
Ralf Corsepius
Forschungsinstitut fuer Anwendungsorientierte Wissensverarbeitung (FAW)
Helmholtzstr. 16, 89081 Ulm, Germany     Tel: +49/731/501-8690
mailto:corsepiu at faw.uni-ulm.de           FAX: +49/731/501-999
http://www.faw.uni-ulm.de